This invention relates to devices for irradiating the body with light of different colors.
Some alternative medicine proponents believe that particular colors of light, applied to the body surface at particular areas can relieve particular ailments. The light is generally provided by an incandescent bulb that passes through specific color filters. Since the light from an incandescent tungsten filament contains substantially all of the wavelengths of light, and only a very small fraction is desired for a particular purpose, most of the light is wasted. It is absorbed in the color filter and often it must be first passed through a heat shield filter to absorb some of the light energy to protect the color filters from deterioration. Most of the color filters employed for this purpose pass through a fairly broad band of wavelengths or colors, many of which may not be useful. Narrow band pass filters are available, but they are quite expensive. It would be useful to have a hand held device that could be selectively adjusted to provide light of particular wavelengths in which all of the electric power were used only for emitting the selected wavelengths.